Heat dissipation device

ABSTRACT

A heat dissipation device includes a fan and a heat sink located at the air outlet of the fan. The heat sink includes a first fin set arranged on a side portion of the air outlet, a second fin set arranged on a central portion of the air outlet and a third fin set. The first fin set includes a plurality of first fins with a first passage is defined between each two neighboring first fins. The second fin set includes a plurality of second fins with a second passage defined between each two neighboring second fins, a width of the second passage is less than that of the first passage. The third fin set includes a plurality of third fins. Each third fin is arranged between two neighboring first fins and divides an outer portion of the first passage away from the outlet of the fan into two third passages.

BACKGROUND

1. Technical Field

The disclosure relates to heat dissipation devices, and particularly to a heat dissipation device incorporating a fin assembly.

2. Description of Related Art

A heat dissipation module is often applied to dissipate heat from heat generating components, such as central procession units (CPUs). Generally, a conventional heat dissipation module includes a centrifugal fan and a fin assembly arranged at an air outlet of the fan.

During operation, the fan generates airflow through the fin assembly to take away the heat of the fin assembly absorbed from the heat generating component. However, an amount of the airflow at two sides of the air outlet is larger than an amount of the airflow at a central portion of the air outlet, therefore, dust will deposit on two laterally sides of the fin assembly corresponding to the two sides of the fan along with the airflow.

Thus, it is desired to overcome the described limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembled view of a heat dissipation device, according to an exemplary embodiment of the present disclosure.

FIG. 2 is an exploded, isometric view of the heat dissipation device of FIG. 1.

FIG. 3 is a disassembled view of a heat sink of the heat dissipation device of FIG. 2.

FIG. 4 is a top plan view of a fan and the heat sink of FIG. 1.

DETAILED DESCRIPTION

FIGS. 1 and 2 show a heat dissipation device 100 in accordance with an exemplary embodiment. The heat dissipation device 100 includes a first heat absorbing substrate 10, a second heat absorbing substrate 20, a heat sink 30, two first heat pipes 70 thermally interconnecting the first heat absorbing substrate 10 and the heat sink 30, a second heat pipe 72 thermally interconnecting the second heat absorbing substrate 20 and the heat sink 30, and a fan 80 arranged a lateral side of the heat sink 30.

In the present embodiment, the fan 80 is a centrifugal fan, which includes a holder 81, a cover 83 engaged with the holder 81 to form a cavity, and an impeller 82 received in the cavity. The holder 81 includes a bottom plate 84 and a sidewall 85 perpendicularly and upwardly extending from a periphery of the bottom plate 84. The bottom plate 84 and the cover 83 respectively define a plurality of air inlets 86 therein. The holder 81 defines an air outlet 87 between two ends of the sidewall 85. A curved tongue portion 88 protrudes inwardly from the sidewall 85, and is adjacent to the air outlet 87.

Also referring to FIGS. 3 and 4, the heat sink 30 is located at the air outlet 87 of the fan 80, and includes two first fin sets 40, a second fin set 50, and a third fin set 60 arranged at an outer side of the heat sink 30 away from the air outlet 87 of the fan 80.

Each of the first fin sets 40 includes a plurality of first fins 42 stacked together. Each first fin 42 is parallel to and spaced from a neighboring first fin 42. Each first fin 42 includes a first main body 420 and a pair of first flanges 422 bent horizontally from a top and a bottom of the first main body 420. In the present embodiment, each first flange 422 of the first main body 420 includes a first portion 423 near the air outlet 87 of the fan 80 and a second portion 425 away from the air outlet 87 of the fan 80. A width of the first portion 423 is larger than that of the second portion 425. In the present embodiment, a width of the first portion 423 is twice as that of the second portion 425. The first potion 423 of the first flange 422 of each first fin 42 abuts against the main body 420 of a neighboring first fin 42. A first passage 43 is defined between the main bodies 420 of each two neighboring first fins 42 for airflow generated by the fan 80 with a width substantially the same as that of the first portion 423 of the flange 422.

The second fin set 50 includes a plurality of second fins 52, two of the plurality of second fins 52 are arranged at opposite outmost sides of the two first fin sets 40, respectively, and the other second fins 52 are stacked together and sandwiched between the two first fin sets 40. Each second fin 52 includes a second main body 520 and a pair of second flanges 522 bent horizontally from a top and a bottom of the second main body 520. In the present embodiment, each second flange 522 has a constant width, which is substantially equal to that of the second portion 425 of the first fin 52. Each second flange 522 of the other second fins 52 abuts against the main body 520 of a neighboring second fin 52. A second passage 53 is defined between each two neighboring second fins 52 for airflow generated by the fan 80 with a width the same as that of the second flange 522. Therefore, the width of the first passage 43 is twice as that of the second passage 53.

The third fin set 60 includes a plurality of third fins 62. Each third fin 62 includes a third main body 620 and a pair of third flanges 622 bent horizontally from a top and a bottom of the third main body 620. A width of the third flange 622 is equal to that of the second flange 522 of the second fin 52 and the second portion 425 of the first fin 42. In the present embodiment, each third fin 62 is arranged between two neighboring first fins 42 at position away from the air outlet 87 of the fan 80. Each third flange 622 abuts against the second portion 425 of the first flange 422. The third fin 62 divides an outer portion of a corresponding first passage 43 away from the fan 80 into two third passages 63. In the present embodiment, a width of the third passage 63 is equal to that of the second passage 53, and the width of the first passage 43 is twice as that of the third passage 63.

In the present embodiment, a top portion of the heat sink 30 near the air outlet 87 of the fan 80 defines a notch 31 for receiving ends of the first heat pipes 70 and the second heat pipe 72. The other ends of the first heat pipes 70 and the second heat pipe 72 are respectively thermal connected to the first heat absorbing substrate 10 and second heat absorbing substrate 20.

In the present embodiment, the first and second heat absorbing substrates 10, 20 are made of metal which has a high thermal conductivity, such as copper, aluminum, or stainless steel. The first and second heat absorbing substrates 10, 20 are respectively configured for contacting electronic elements and absorbing heat generated therefrom.

In the heat dissipation device 100, the two first fin sets 40 are respectively arranged at two laterally side portions 89 of the air outlet 87 of the fan 80, the second fin set 50 is arranged at a central portion 90 of the air outlet 87. During operation of the heat dissipation device 100, the impeller 82 of the fan 80 rotates and drives airflow from the air inlets 86 into the cavity, and then to the air outlet 87. Air pressure in the two laterally side portions of the air outlet 87 is larger than air pressure in the central portion of the air outlet 87, and the width of the first passage 43 is larger than that of the second passage 53; therefore, most dust enter the two laterally sides of the air outlet 87, and flow through the first passages 43 of the first fin sets 40, and then vent from the third passage 63 along with the airflow. Additionally, the width of each of the third passage 63 and the second passage 53 are lesser than that of the first passage 43; therefore, it can prevent dust from entering the heat sink 20 via the second and third passages 53, 63.

It is to be further understood that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A heat dissipation device comprising: a fan defining an air outlet at one side thereof, the air outlet comprising a first portion and a second portion, air pressure in the first portion being larger than air pressure of the second portion; and a heat sink being located at the air outlet of the fan, the heat sink comprising a first fin set arranged at the first portion, a second fin set arranged at the second portion and a third fin set, the first fin set comprising a plurality of first fins stacked together with a first passage being defined between each two neighboring first fins, the second fin set comprising a plurality of second fins stacked together with a second passage being defined between each two neighboring second fins, the first passages and the second first passages communicating with the air outlet of the fan, a width of the second passage being less than that of the first passage, the third fin set comprising a plurality of third fins, each third fin being arranged between two neighboring first fins away from the air outlet of the fan, each third fin dividing an outer portion of the first passage away from the outlet of the fan into two third passages.
 2. The heat dissipation device of claim 1, wherein a width of the first passage is twice as that of the second passage.
 3. The heat dissipation device of claim 1, wherein a width of the second passage is equal to that of the third passage.
 4. The heat dissipation device of claim 1, wherein the fan is a centrifugal fan, the first portion being two opposite side portions of the air outlet, and the second portion being a central portion of the air outlet.
 5. The heat dissipation device of claim 1, wherein each first fin comprises a first main body and a pair of first flanges bent horizontally from a top and a bottom of the first main body, each first flange being abutted with a first flange of a neighboring fin, the first passage being formed between every two adjacent fins.
 6. The heat dissipation device of claim 5, wherein each second fin comprises a second main body and a pair of second flanges bent horizontally from a top and a bottom of the second main body, each second flange being abutted with a second flange of a neighboring second fin, the second passage being formed between every two adjacent second fins.
 7. The heat dissipation device of claim 6, wherein each of the third fins comprises a third main body and a third flange bending from the third main body, a width of the second flange and the third flange being less than that of the first flange.
 8. The heat dissipation device of claim 6, wherein each third fin comprises a third main body and a pair of third flanges bent horizontally from a top and a bottom of the third main body.
 9. The heat dissipation device of claim 8, wherein each first flange extending from a top edge of the first main body comprises a first portion near the air outlet air outlet of the fan and a second portion away from the air outlet of the fan.
 10. The heat dissipation device of claim 9, wherein a width of the second portion of the first flange is less than that of the first portion of the first flange, a width of the second flange being less than that of the first portion of the first flange, a width of the second flange being less than that of the first portion of the first flange.
 11. The heat dissipation device of claim 10, wherein a width of the first portion of the first flange is twice as that of the second portion of the first flange.
 12. The heat dissipation device of claim 10, wherein a width of the first portion of the first flange is twice as that of the second flange.
 13. The heat dissipation device of claim 10, wherein a width of the first portion of the first flange is twice as that of the third flange.
 14. A heat dissipation device comprising: a centrifugal fan defining an air outlet at one side thereof; and a heat sink being located at the air outlet of the fan, the heat sink comprising two first fin sets arranged at two laterally side portions of the air outlet, a second fin set arranged between the first fin sets, and a third fin set, the first fin set comprising a plurality of first fins with a first passage being defined between each two neighboring first fins, the second fin set comprising a plurality of second fins with a second passage being defined between each two neighboring second fins, the third fin set comprising a plurality of third fins, each third fins being sandwiched between two neighboring first fins, a third passage being defined between a third fin and a neighboring first fin, a width of the second passage being less than that of the first passage, and a width of the third passage being less than that of the first passage.
 15. The heat dissipation device of claim 14, wherein a width of the second passage is equal to that of the third passage.
 16. The heat dissipation device of claim 14, wherein a width of the first passage is twice as that of the second passage.
 17. The heat dissipation device of claim 14, wherein a width of the first passage is twice as that of the third passage. 